جستجوی مقالات مرتبط با کلیدواژه « rankin cycle » در نشریات گروه « فنی و مهندسی »

Steam power plants are an advanced and complex design of the Rankin steam-liquid cycle. Therefore, understanding the concepts of effective parameters in increasing energy and exergy efficiency and also exergoeconomic are very important. The purpose of this study is to investigate the three basic scenarios of steam power plants, till the required changes in design and its effects on power plant efficiency to be determined. The third scenario has a preheater, a deaerator and two turbine extraction. The second scenario has a turbine extraction and preheater. In third scenario, energy and exergy efficiency are 20.74% and 26.91%, respectively. it’s increases of energy and exergy efficiency relative to second scenario are equal to 19.13% and 9.48%, respectively. Exergoeconomic analysis has shown that boiler and turbine have the highest total cost of investment, maintenance and exergy destruction, hence special attention should be paid to this equipment. The high relative cost factor of the boiler (r) indicates that the boiler efficiency can provide an overall improvement in the cost of this equipment. This can be done by reducing the exergy destruction by preheating and reducing losses and use of excess air. The Exergoeconomic coefficient of fk turbine is high. This means that to reduce the cost of the turbine, the possibility of reducing parameters such as inlet steam temperature, turbine pressure and it’s efficiency should be given more attention.

Nowadays, there are some worries about the increasing temperature of earth and the pollution of fossil burning, hence using of new techniques in increasing power plant efficiency are very important. In this paper three structure layouts of turbine and power plant elements have been presented and The energy and the exergy losses for each component, energy and exergy efficiency of overall plant and irreversibility have also been determined using mass, energy and exergy balance equations. The energy and exergy analysis have been calculated in traditional and sub-system techniques namely boiler subsystem, steam cycle or thermal cycle subsystem and cooling tower subsystem. Results of exergy analysis in different steam power plants show that the major source of exergy destruction is the boiler. Suitable power plant design and its energy and exergy efficiency will be presented to client, till to support project and have capital investment on it. In this paper, in addition to suggested proportional power plant designs, the technical suggestions have been also presented to increase the power plant efficiencies.